Forming ways or ducts in plastic material



Oct. 16, 1928. 1,687,879

T. E. MURRAY FORMING WAYS OR DUCTS IN PLASTIC MATERIALS Filgd Aug. 19,1925 2 Sheets-Sheet 1 g-mwntoz 7710 7/67 5 5. Murray MQM Gum/mm;

T; E. MURRAY FORMING WAYS-0R DUCTS IN PLASTIC IA'I'ER'IALS Oct. 16,1928.

Filedjug. 19, 1925 2 sheets-sheet 2 Sammie; 760/7745 5 Murray similarPatented Oct. 16, 1928.

unites sT 'rnomasn. MURRAY, or BROQKLYN, new YORK.

FORMING WAYS-OR DUCTS IN PLASTIC MATERIAL. I

Application filed Aug'ust 19, 1925; Serial No. SL249.

My invention aims to provide methods and apparatus tor forming ducts orraceways in floors or other structures of concrete or other plasticinatcriahsuch as are commonly use-d for laying Wires'oi' pipes inabuilding. The accompanying: drawingsillustrate embodiments of theinvention.--

Figs. 1, 2 and 3 are ve 'ti'cal sections through a floor-illustrating;ditl'erfencesin detail Figs. & and 5 are respectively a side elevationand plan of an apparatus for applying the process;

Fig. 6 illustrates in perspective a floor g'rooved'by the process of 5with a device for forming an outlet to the ceiling below;

Figs. 7 and 8 illustrate supplementary dc vices used in moloing acrossing'and an out- I c p I Fig. 9 illustrates the work done" by. thesedevices; r 7

Fig. 10 is a perspective view of a device for forming a junction box;and

Figs. 11 and-12 are cross-sections showing the invention applied to themaking of ducts in blocks of concrete.

In building; a floor, a slab 1 of strong con crete is first placed Onthis is a fillil ofmoist Cinders or ofcomparatirely Weak cinderconcrete; on the top of ivhich is another slab'S ofstrong' concrete.

I propose to make ducts in sucha floor by forming grooves in the top. ofthe cinder till with a lining 5 or". line concrete: or other durablematerial. The implication of the layer 3 of concrete above closes thegrooves to form a conduit. Where a circul'arconduit is desired I proposeto lay in the groove a core 1, Fig. 10, of high grade rubber on Whiclthe'layer of concrete Zis poured. .Vheirthe latter has hardened, thecore will endwise, contractinqit in cross-section so as to release itfrom the surrounding}; concrete and to permit its Withdrawal. Atcrossings or other outlet points, an outlet box may be formed similartothat shown in Fig. 3 comprising; a vertical cylindrical recess 6communicating with the conduits which are indicated as a Whole at 7 andwith an enlarged cylindrical portion 8 at the upper end. Such an outletbox may be formed for example by means of a core (Fig. 10) having areduced lower portion 9 and a larger upper portion 10. Theends of theduct cores 6 abut this box core. The concrete being hardened, the boxcore is Withdrawn and the duct cores 6 can be pulled endwise throughtheopening. 7

the upper slab 3 of concrete.

' down to the ceilin; at 12.

, slightly moistened cement or mixture.

- thin layer on top on the centering device. 1

and belowbe pulled v the same asin Fig. 6', and having Another way ofcompleting the duct is shown in Fig. 2; A plate 11 is laid. over the'QTOOVQ formedjwith the'lining 5, and supports In this connection I haveshown an opening or outlet box I 7 Metal anchors 13 are embedded in theceiling adjacent to the opening 1'2 to'support a lighting or similarfixture and are grounded to the beams as shown. V 5

The groove can be rapidly and economically made in the cinderconcreteby-means of a roller 14 (Figs. 1 and 5) having a periphery ofthe desired shape in cross-section and a handle 15' by which it ispulled across the cinder in the desired line; the roller having weightenough to press the cinder into the desired grooved shape. \Vhere alining of concrete is desired to the groove, a hopper 16 is handle infront of the roller, carryingdry or Aflat roller 17 travels justbehindthe opened lower end of the'hopper and spreads cement in a of thecinder; I Then when reinforce the wall of fastened to the the heavyroller 14 advances, it presses out the cement layer and the cinder belowto form a a cement-lined groove as in Fig. 1. Fig. 6 shows the top ofthe bed of cinder concrete groovedwith linings 5 of cement.

To provide an outlet to the ceiling below, a 5

pointed iron rod 18 is used with handles 19. By putting;sufiicient'pressure on this 'ancl turningit'back and forth, it" may beforced through the cinder and drilled through the concrete slab 1.

I Fig. 7 illustrates the making of an outlet box at a' crossing withopenings both iabove. 7 At the intersection atool (Fig. 8) is usedhavinga shank. 18 and handles 19, at a proper height a cylindricalportion "20 of the desired diameter. First, a metal oenoering device orguide is used comprising troughs 21 (Fig. 7) with flanges 22 at the top"connected across the corners by Webs 23; with acircular opening at thecenter in which the part 20 I of the tool fits.

This serves to center the tool and at the same time to guard againstinjury to the corners of the concrete. ing form is laid in the grooveswith linings 5, after which the tool of Fig. .8 is thrust down into theconcrete in the manner previously described. V

Fig. 7 shows also the use of a simple rod 18 for making an outlet in theceiling below,

The concretit to locate the tool 18 and to prevent breaking the edges ofthe concrete therewith.

After these operations, the forming devices will be removed, leaving thetop ot the cinder bed as in Fig. 9. Thereupon the core 9l0 (Fig. 10 willbe set in the central opening 2st and the cores A abutted against it andlaid in the desired lines. The top layer of concrete 8 will then beapplied and the rubber cores withdravm as above described.

The invention may be applied in many other structures than lloors andwithout the reinforcing lining 5. Figs. ll and 12 for-example illustratetl'ie making oi? a hollow reinforced block of con First a slab otconcrete is laid in a mold 26. While the concrete is still soft, a heavyor weighted roller 27 is drawn along the top of it and forms asemi-circular groove 28 (Fig. 12). Reinforcing Wires or rods 29 are alsolaid on the top of the slab. Arubber or similar removable core is laidin the groove 28 and a second slab 3-0 is cast thereon and preferablypressed down and smoothed by a flat roller 31 drawn over the top. Therubber core forms the semi-circular upper portion 32 of the duct. Or thegroove 28 may he covered in various other Ways to form a closed duct,using either a removable core or support for the upper concrete or apermanent support such as the plate 11 in Fig. 2, which may be ofvarious shapes in cross section. The

' groove 28 may be lined with line cement or concrete if desired. And inall the constructions described, other materials than cement or concretemay be used for the lining of the groove. Where dry cement is used, thewater in the cinder fill unites with it and makes the lining practicallyintegral with the material below. 3

The outlets into the floor above may be closed with a thin plug leveledoil. with the floor and made of plaster or other easily removablematerial.

The same scheme may be applied to the making of conduits in otherlocations. Street conduits, for example, may be made in this way, thesoft earth, generally moist, being substantially theequiva'lent of thecinder fill and other plastic materials referred to. The apparatus ofFig. 4- Will form a groove in the earth and line it, after which it maybe covered by any of the methods above de scribed. v

v In Figs. 1 and 2- I have shown, the grooves formed for a depth equalto the entire diameter oi the proposed duct. In the other figures I haveshown the groove formed to a depth of only. halt thediameter. In thelat, ter case the superposed layer will enclose the upper half oi theduct as in Fig. 12, for ex ample.

Various modifications oi" the described embodiments may be made withoutdeo'artin'g from the invention asdelined in the following claims.

What I claimis 1. In the making a floor containing a layer ofcomparatively poor plastic material, the method of forming grooves insaid material which consists in applying a comparatively rich plasticmaterial to the top of said layer and passing over the same a roller having a'periphery of the desired cross-section of the grooveand presseddown sufliciently to force the comparatively rich material down into thecomparatively poor material and to form a groove lined with suchcomparatively rich material. V 3

2. The method of making ducts in plasticmaterial Whichconsists inproviding a bed of comparatively poor material laying a Coating thereonof richer material, forming a groove in a coated portion of said bedwith a lining of such richermaterial andapplying a second bed ofmaterial above-the first to close said groove andform a duct.

3. In the making of a floor or the like or plastic material, the methodof forming Ways therein which consists in applying "permanent limngmaterial thereon and presslngthe .lining material andthe supportingplastic.

material at the same time to form them into a grooved shape.

l. In the forming o'tways inplastic mav terial, the method whichcomprises. apply-1 ing a plastic lining material to a plastic toundation material and pressing both such ma terials at the same time toform them into a grooved shape. f I: I In Witness whereof, Ihavehereunto signed my name.

THOMAS E. MURRAY.

